CVE-2026-97876
MEDIUM
6,4
Source: [email protected]
Attack Vector: local
Attack Complexity: high
Privileges Required: high
User Interaction: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: high
Description
AI Translation Available
A local attacker with control over GRUB's configuration can bypass lockdown restrictions when booting with Secure Boot and load an unsigned GRUB module, while GRUB continues to report lockdown is enabled.
The vulnerability is caused by insufficient validation of the MMIO base address passed to the GRUB serial command. GRUB does not validate that the base address corresponds to a UART device, rather than being an arbitrary memory address. This allows an attacker to trick GRUB into writing non-arbitrary data at an attacker-controlled address, including resetting the grub_file_verifiers list in a way that disables the subsequent verification of loaded modules.
822
Untrusted Pointer Dereference
IncompleteCommon Consequences
Security Scopes Affected:
Confidentiality
Availability
Integrity
Potential Impacts:
Read Memory
Dos: Crash, Exit, Or Restart
Execute Unauthorized Code Or Commands
Modify Memory
Applicable Platforms
Languages:
Memory-Unsafe, C, C++
https://gitlab.freedesktop.org/gnu-grub/grub/-/commit/26beaa3b2720fefdc4d04c1ae…
https://www.openwall.com/lists/oss-security/2026/09/13/5